Biomedical instrumentation requires the use of ultraviolet (UV) lasers to implement high sensitivity detection techniques. Examples include laser-induced fluorescence, confocal microscopy, and flow cytometry. The objective of this phase 1 program is to develop solid-state UV laser sources based on the novel nonlinear optical material periodically poled lithium tantalate (PPLT). This material has recently emerged as a practical candidate for laser frequency conversion using the technique of electric-field ferroelectric poling developed at Stanford University and Lightwave Electronics. PPLT has high gain, engineerable properties, and transparency covering the UV range around 300 nm where there are currently no suitable nonlinear optical materials. The long-range goal is to develop sources in the 260-360 nm range with power levels around 100 mW and packaging suitable for inclusion in clinical instrumentation. The specific demonstration undertaken in this Phase I effort will involve frequency conversion of diode-pumped solid- state Nd:crystal lasers. The approach is also compatible with direct frequency conversion of diode lasers. These UV sources will have the capability to replace existing gas laser technologies with substantial improvements in efficiency, compactness, reliability, and cost resulting in improved performance and utility of biomedical instruments. PROPOSED COMMERCIAL APPLICATION: The solid-state UV laser sources being developed in this program will lead to biomedical instrumentation with improved performance in the spectral range approximately 300 nm which is difficult to obtain with current technology. Examples include DNA sequencing, flow cytometry, high-performance liquid chromatography, laser-induced fluorescence, and confocal microscopy.